This invention relates to copolymeric materials having dye mordanting capability. More particularly, it relates to mordant copolymers especially suited to application in photographic diffusion transfer products and processes.
Diffusion transfer photographic products and processes have been described in numerous patents, including, for example, U.S. Pat. Nos. 2,983,606; 3,345,163; 3,362,819; 3,594,164; and 3,594,165. In general, diffusion transfer photographic products and processes involve film units having a photosensitive system including at least one silver halide layer, usually integrated with an image-providing material, e.g., an image dye-providing material. After photoexposure, the photosensitive system is developed, generally by uniformly distributing an aqueous alkaline processing composition over the photoexposed element, to establish an imagewise distribution of a diffusible image-providing material. The image-providing material is selectively transferred, at least in part, by diffusion to an image-receiving layer or element positioned in a superposed relationship with the developed photosensitive element and capable of mordanting or otherwise fixing the image-providing material. The image-receiving layer retains the transferred image for viewing and in some diffusion transfer products, the image is viewed in the layer after separation from the photosensitive element, while in other products, such separation is not required.
Various polymeric materials have been utilized as mordants in photographic products and processes including those of the diffusion transfer type. Thus, polymeric mordants suited to application in diffusion transfer products and processes for the formation of photographic images in dye are described, for example, in U.S. Pat. No. 3,148,061 (issued Sept. 8, 1964 to H. C. Haas); U.S. Pat. No. 3,758,445 (issued Sept. 11, 1973 to H. L. Cohen et al.); U.S. Pat. No. 3,770,439 (issued Nov. 6, 1973 to L. D. Taylor); and in U.S. Pat. No. 4,080,346 (issued Mar. 31, 1978 to S. F. Bedell). The advantageous utilization of a particular mordanting material in a photographic product or process will oftentimes depend upon the particular requirements of a photographic product or process and deficiencies or disadvantages associated with the utilization of a particular mordanting material may be observed. Thus, deficiencies in mordanting capacity with respect to one or more dye materials desirably utilized or the formation of a photographic image exhibiting haze, yellowing or other related image defects may be observed. Additionally, difficulties in the synthesis or preparation of a polymeric material exhibiting desirable mordanting capability or in the efficient coating of a suitable image-receiving layer containing a polymeric mordant may impose formidable limitations upon practical utilization of a particular mordanting material.
It is an object of the present invention to provide polymeric mordants exhibiting efficient dye mordanting capability.
It is another object of the present invention to provide polymeric mordants exhibiting such mordanting capability and adapted to utilization in photographic products and processes.
Still another object of the present invention is the provision of polymeric mordants useful in photographic diffusion transfer products and processes in the formation of dye images free of objectionable haze, yellowing or other related image defects.
It is still another object of the present invention to provide such polymeric mordants capable of ready synthesis and efficient utilization in the preparation of coated imagereceiving layers containing such polymeric mordants.
Other objects of the present invention will become apparent from the description appearing hereinafter.